High frequency of sister chromatid exchanges in lymphocytes of the patients with Behçet's disease.

Behçet's disease (BD) (OMIM 109650) is an immunogenetically based multisystem disease, characterized by iridocyclitis, arthritis, orogenital ulcerations and pustular skin lesions. Viral and autoimmune etiologies have been suggested and HLA-B5 has been found to predominate in BD. The disease is most seen in Turkey and Japan. Although familial cases have been reported, the mode of inheritance is not clear. To determine the genetic instability in BD, sister chromatid exchange (SCE) analysis has been performed on peripheral lymphocytes in 23 patients and 20 healthy controls. We found significantly higher SCE rates in the patient group (p < 0.0001). Our results may indicate that genetic impairment and genetic instability may play an important part in the etiology of BD.